WASHINGTON -- When he was working on a poultry processing line in northern Alabama last year, Jorge Polanco-Mercado watched new workers come and go all the time. Many of them didn't even finish their first shift before quitting.

They all fled so quickly, Polanco-Mercado said, because they were intimidated by the speed of the processing line.

"Some would come into the plant and work one hour, and resign because it was too fast to keep up with," the 33-year-old from Puerto Rico said in Spanish through a translator, asking that his former plant not be named. Polanco-Mercado's job was to hang individual chickens on hooks, preparing them for disassembly down the line, filling a quota of between 57 and 60 chickens per minute, or roughly one every second, he said.

"Every week they had to hire new workers," he said.

So Polanco-Mercado was surprised to learn that the U.S. Department of Agriculture and the White House have proposed new poultry inspection rules that would allow many plants to speed up processing lines. Although the rules are intended to overhaul food safety, the potential impact to worker safety has drawn the concern of the United Food and Commercial Workers Union (UFCW), which represents thousands of poultry workers, as well as worker advocacy and legal aid groups.

"We think it’s a bad idea," said Tom Fritzsche, a staff attorney at the Southern Poverty Law Center, which handles many poultry worker cases. "The most common complaint workers have is that the lines as they go right now are already too fast."

By expanding a pilot program already underway, the USDA's proposed rule would pull many of the agency's Food Safety Inspection Service (FSIS) inspectors, who examine chickens for blemishes and defects, off the production line in poultry plants. Although one inspector would remain on the line, private plants would be mostly responsible for inspecting chickens, while FSIS employees would focus on detecting bacteria and other invisible dangers. The change is projected to phase out 800 inspection jobs, and save around $95 million over three years. The USDA said the rule changes would help update an outmoded system.

The problem for workers, advocates say, is that the presence of human inspectors serves as the primary governor of line speed in plants. With USDA inspectors out of the picture, the proposed rule would allow some plants to move from a maximum of 70 to 140 birds per minute to a maximum of 175, a potential boon to the efficiency-minded poultry industry.

The National Chicken Council, a trade group that represents companies like Tyson Foods, approves of the proposed system, arguing that it would modernize the inspection process. Tom Super, a spokesman for the council, said the changes to line-speed regulations wouldn't necessarily impact workers.

"Just because the pilot project allowed plants to operate at higher line-speeds as in the proposed rule, it does not mean all plants will continuously operate at this higher line speed," Super said in an email.

The UFCW disagrees, arguing that many plants will inevitably operate at the highest speeds allowed. Mark Lauritsen, head of the union's food packing and processing division, said that with increased line speeds come higher injury rates.

"I think it's about squeezing more production out of overworked workers," said Lauritsen. "This is the poultry industry's rule ... They squeeze every ounce of profit out of workers, and they notoriously underreport injuries."

Many of the workers inside poultry plants are immigrants from Latin America, and refugees from Africa and elsewhere, while a sizable portion is believed to be undocumented, according to national legal advocacy groups. Lawsuits from workers have become common in the industry, with employees accusing companies of violating wage laws under the Fair Labors Standards Act.

As in many meat processing jobs, poultry line workers are generally low-paid and suffer high injury rates compared to other fields. Many workers must perform the same motions throughout the day, like Polanco-Mercado, often handling dangerous equipment. Though official injury rates have generally declined, some plants tend to underreport workers' injuries, according to an in-depth 2008 investigation by the Charlotte Observer.

Amid concerns from worker advocates, the USDA announced Thursday that the public-comment period for the new proposed rule would be extended, giving interested parties a chance to weigh in. Christina Spring, a spokeswoman for the National Institute for Occupational Safety and Health (NIOSH), a research arm of the Centers for Disease Control and Prevention, said the institute has started to work with the USDA to see what the proposed rule could mean for workers. Given that such studies can take months or longer, the UFCW is asking that the White House and USDA delay the rule until the research is completed.

It isn’t clear to what degree the USDA or the White House's rulemaking review branch, the Office of Information and Regulatory Affairs (OIRA), consulted with the Labor Department about the proposal's effect on plants' workers. None of those agencies responded when asked by The Huffington Post whether the Occupational Safety and Health Administration (OSHA), the Labor Department's worker safety agency, had reviewed the rule before it was proposed.

Cass Sunstein, the head of OIRA, which reviews such rules on behalf of the White House, penned an op-ed last month explaining how the administration was working to review old regulations to see if they justify costs. He cited the new USDA poultry proposal as a commonsense, cost-saving change: "The Department of Agriculture has proposed to streamline antiquated poultry inspection requirements, allowing companies to choose a more flexible approach with five-year savings in excess of $1 billion."

For Polanco-Mercado, the idea of faster production lines is hard to contemplate. He often got in trouble with supervisors when he missed a hook with a chicken, he said, and his year on the line left him with pain in his wrist and arm that made it hard to sleep.

"It’s a very repetitive job that requires you to use a lot of strength," Polanco-Mercado said. "And it’s a job where you don't get any relief."

Correction: This post originally stated that no federal inspectors would be inspecting chickens under the proposed rule. In fact, one inspector would be placed at the end of the production line.